Motor fuel containing hydrazones



United States Patent Office Jersey No Drawing. Filed June 26, 19,61, Ser. No. 119,263 Claims.- (Cl. 44-64) This, invention relates to motor fuels, particularly to gasoline fuels for use in internal combustion engines. Specifically, it relates to gasoline which is inhibited against oxidation degradation by incorporation therein of a minor amount of specific hydrazones.

The gasolines produced for use in modern internal combustion engines usually boil through the range of 50 F. to 425 F. and are blended from various components recovered from processing crude petroleum. For example, a gasoline may contain various amounts of catalytic gasoline, straight-run gasoline, catalytic reformate, C and C polymer gasoline, thermal gasoline, butanes, pentanes, octanes, and aromatic components such as toluene and benzene. While certain of these components have suitably high anti-knock value, they may be unsatisfactorilyv stable against oxidation. The processed hydrocarbons, e.g., thermal gasoline, are notably subject to oxidation attack in normal storage with the attendant formation of gums, resins, etc., and, usually, severe color degradation. The oxidation products have a deleterious effect on engine wear and contribute significantly to the resinous deposits which form on pistons, cylinder walls, rings, etc., within the internal combustion engine.

There are many comercially available oxidation inhibitors which are used in motor fuels to suppress oxidation degradation. However, many of these inhibitors are insoluble in the fuel and thus have a tendency to drop out during storage. Further, many inhibitors are relatively high molecular weight compounds and sometimes remain as a residue when the fuel evaporates in, say, the carburetor. Still further, many oxidation inhibitors when incorporated into gasoline will significantly reduce the anti-knock value of the motor fuel composition.

The use of unsubstituted hydrazine as an additive in gasoline is known in the art. However, hydrazines are substantially insoluble in hydrocarbons, and, therefore, must be injected into the motor fuel at some point other than the storage system. On the other hand, it has been found that hydrazones are substantially soluble in hydrocarbons and could therefore be added to motor fuel during the blending process.

According to the present invention, the addition of a minor amount of specific hydrazones or mixtures thereof to motor fuel significantly improves the oxidation stability of the fuel.

As used herein, the term oxidation stability embraces color degradation, gum formation, and oxygen attack susceptibility of the fuel.

The specific hydrazones contemplated by the present invention are those defined by the formula 3,239,320 Patented Mar. 8, 1966 ticing this invention include formaldehyde-nitrophenylhydrazone, formaldehyde-dinitrophenylhydrazone, acetaldehydenitrophenylhydrazone, acetaldehyde dinitrophenylhydrazone, propionaldehyde-nitrophenylhydrazone, propionaldehyde dinitrophenylhydrazone, benzaldehyde-nitrophenylhydrazone, benzaldehyde dinitrophenylhydrazone, methyl-ethyl-ketone-nitrophenylhydrazone, methylethyl-ketone dinitrophenylhydrazone, benzaldehyde cyclopentyl-2,4-dinitrophenylhydrazone, benzaldehyde ethyl-2,4-dinitrophenylhydrazone, and the like. A particularly suitable hydrazone is propionaldehyde-p-nitrophenylhydrazone. A distinctly preferred hydrazone is benzaldehyde-2,4dinitrophenylhydrazone.

The benefit obtained from the present invention results from blending 0.0001 percent to 1.0 percent by weight of hydrazone into the gasoline. Preferably, the amount of hydrazone used is from 0.05 percent to 0.5 percent of the fuel. Theblending of the hydrazones into the motor fuel can be performed by any convenient manner or at any convenient stage of blending the motor fuel composition. They can be added as pure components or can be diluted with one or more of the heavier blending components to be used.

It is recognized that the motor fuel of the present invention may contain other non-gasoline components such as tetraethyl lead, light lubricating oils, phosphorus compounds, other oxidation inhibitors, and the like.

The benefits obtained from the motor fuel composition of the present invention are illustrated in the following examples:

Example 1 Peroxide N0. after Weeks in Storage Hydrozone ZA-dinitrophenyl 0 p-Nitrophenyl 0 Phenyl 0 MHO The above data indicate that the dinitrophenyl hydrazone is a surprisingly good inhibitor. It is noted that the mononitrophenylhydrazone is also satisfactory.

Example II The experiment of Example I was repeated except that oxidation stability of the fuel was measured by determining the existent gum (ASTM D-381-58T) in the fuel. The results are tabulated in the following table:

AS'IM Gum after Weeks in Storage Hydrazone 2,4-dinitrophenyl l0. 4 Phenyl These data show that the dinitrophenyl hydrazone is a significantly better inhibitor against gum formation than the phenylhydrazone. The mononitrophenylhydrazone would be expected to be slightly better than phenylhydrazone but not nearly as efficient as the dinitro compound in inhibiting gum formation in gasoline.

Example III Approximately 0.1 percent by weight of propionaldehyde-p-nitrophenylhydrazone was added to another sample of the base stock of Example I and tested for oxygen bomb induction time (ASTM D52555). The initial fuel with no inhibitor tested 3 hours. The fuel plus inhibitor tested 8+ hours. Similar results were obtained using 0.1 percent propionaldehyde-2,4-dinitrophenylhydrazone.

Example IV Solutions of the 2,4-dinitrophenylhydrazones of the following compounds in 0.0005 percent by weight concentration in a commercially available gasoline visually showed essentially no color degradation after two months in storage at 80 F.: formaldehyde, acrolein, butanal, and isobutanal. The gasoline Without any added inhibitor was visually discolored after being subjected to the same storage conditions.

I claim:

1. A motor fuel composition comprising a major amount of gasoline and a minor amount of hydrazone defined by the formula R1 R Rz \R4 References Cited by the Examiner UNITED STATES PATENTS 1,906,044 4/ 1933 Burk 4464 2,942,957 6/ 1960 Wojcik 4464 3,010,939 11/ 1961 Dinbergs 252403 FOREIGN PATENTS 799,923 8/ 1958 Great Britain.

DANIEL E. WYMAN, Primary Examiner.

JULIUS GREENWALD, Examiner. 

1. A MOTOR FUEL COMPOSITION COMPRISING A MAJOR AMOUNT OF GASOLINE AND A MINOR AMOUNT OF HYDRAZONE DEFINED BY THE FORMULA 